Ball grinding machine



Aug. 8, 1933. G. F. MATTEsoN BALL GRINDING MACHINE 4 Sheets-Sheet 1 Original Filed Dec. 18

H15 ATTO/NEW AU8 8, 1933- G. F. MAT'rEsoN 1,921,536

BALL GRINDING MACHINE original Filed n'ec, 18, 1930 4 sheets-sheet 2 Aug. 8, 1933. G. F. MAT'rEsoN BALL GRINDING MACHINE.

Original Filed Dec. 18. 19250 4 Sheets-Sheet 3 //v VENTO@ s G50@ GE' F MA TTEso/v,

H/S ATTORNEY Aug. s, 1933. 'Q F MATTESQN 1,921,636`

BALL GRINDING MACHINE Original Filed Dec. 18, 1930 4 Sheets-Sheet 4 l ,/NVE/vTo/Q.: 650265 E MATTEso/v,

H/s A ,TTOQ/VEY Patented Aug. 1933 UNITED STATES PATENT OFFICE Application December 18, 1930, Serial No. 503,241 Renewed June 21, 1933 11 Claims.

rlthis invention relates to ball grinding machines and comprises all the features of novelty herein disclosed. In the well-known Hoffmantype ball grinding machine, it is the practice' to feed balls by gravity to grooved grinding rings one of which is rotated. The speed at which the balls are delivered to the grooves is so slow that the rotary abrading ring will make a complete revolution oftener than a ball can be fed into a given groove. Accordingly the machine does not, at one time, grind on the average as many as one ball per groove. An object of this invention is to provide mechanism for increasing the production of ball grinding machines as by feeding balls to grinding members at high speed. Another object is to provide differential feeding mechanism for delivering balls to grooved grinding members at approximately the half velocity of the particular ygrooves to which the respective `balls are led so that, upon contact with said grooves, the acceleration or retardation will be reduced to a minimum. Another object is to provide feed mechanism capable of varying the spacing of the balls between the grinding members. Still another object is to provide improved mechanism for maintaining correct adjustment between hopper and chutes on the one hand and between chutes and grinding members on the other hand. Yet another object is to provide improved mechanism for maintaining a predetermined pressure between grinding members and balls during grinding.

To these ends and to improve generally and in detail upon machines of this character, the invention further consists )in the various matters hereinafter described and claimed. In its broader aspects, the invention is not necessarily limited to the specific construction selected for illustrative purposes in the accompanying drawings in which Fig. 1 is a longitudinal vertical section with some parts in front elevation.

Fig. 2 is a side view. partly broken away, of ,y

the feed mechanism.

Fig. 3 is a vertical sectional view mechanism.

Fig. 4 is an end view, partly in section, of one of the grinding members and associated parts.

Fig. 5 is an enlarged side view of one of the feed wheels.

Fig. 6 is an enlarged plan view of a plate.

Fig. 'l is an enlarged side view of certain partitions and associated parts.

Fig. 8 is an end view of Fig. 7.

of the feed Fig. 9 is an enlarged side view Fig. 10 is an end view of Fig. 9. Fig. 11 is an enlarged end view o.' a chute plate. Fig. Fig. plate.

Fig. 14 is an end view of Fig. 13. Fig. 15 is an enlarged side view of a chute plate.

Fig. 16 is an end view of Fig. 15. Fig. 17 is a plan view of a bar. Fig. 18 is a side view of a modified form o1 feed wheel.

Fig. 19 is an end view of Fig. 18. 70 The members 10 and 12 between which the balls are ground have series of mating concentric grooves 14 for the balls. Member 10 is preferably a cast iron ring which is interrupted at one side as will appear for feeding in and taking out the balls. Member 12 is preferably a ring grinding wheel secured to a ring 16 fastened to a disc 18 by bolts 20 whose heads are countersunk into a holding ring 22. The disc 18 is threaded on one end of a spindle 24 80 which is journalledfor rotation in a single row ball bearing 26 and a double row ball bearing 28. The bearing 26 is mounted with its outer race ring free to float or slide in a bushing 30 carried by the frame or housing 32. Bearing 28 is 85 secured in a bushing 34 of the housing against a shoulder 36 by a closure plate 38 fastened to the housing. Another closurel plate 40 is secured to the opposite end of the housing and between this plate and the disc 18 are over- 90 lapping guard plates 42.

The bearing inner race rings are spaced by a sleeve 44 and the hub 46 of a driving gear is keyed on the spindle and clamped by a threaded cup or nut 48 which has a hexagonal portion 95 49. A sleeve 50 is carried in a recess of the cup and, in a recess of lesser depth, is a ball thrust bearing 52 which abuts against a flange 53 of a sleeve 54, a closure plate 56 being attachedV to the cup 48 and enclosing the flange 53. A 100 second ball thrust bearing 58 is seated in the sleeve 54 and held by a retaining plate 60. The outer ring of the thrust bearing abuts against a nut 62 which is threaded for adjustment on a shaft 64 which extends longitudinally through- 105 out the length of the machine. A portion of the of a plate.

12 is a plan view of Fig. 11. 60 13 is an enlarged side view of a cover Ashaft adjacent to the threads is squared and passed through a square opening in a flange 66 of the sleeve 54 to hold the sleeve from rotation.

'Ihe opposite or right hand end of the shaft 110 sides backing up the ends of a hardened fulcrum pin 72 which bears against the end face4 of a sleeve 74' which is slotted at 75 to receive the lever and provided with a square hole 76 keying it to the forked end of the shaft. The lower end of the lever 70 has a fork pivoted by a pin 78 to any one of a series of round openings 80 in a link 82 connected by a pivot pin 84to the short arm 85 of a bell crank lever 86 which is pivoted at 88 to a bracket 90 on the frame. The longer arm of the bell crank lever acts as a scale beam and has a set of round holes 92I in which a pin 94 can be selectively placed to support a stirrup 96 carrying a weight 98. The two sets of openings with the removable pins provide for varying the leverage exerted by the weight at the fulcrum pin 72 and at the pivot pin 68 of the lever.

The sleeve 74 is pressed axially by the lever and weight against a Washer 100 which abuts against a coiled spring 102 carried in a recess of a sleeve 104 which is slidable in a bearing 105 having a cap 106. The sleeve 104 has an integral flange or disc 108 to which the nonrotary abrading member 10 is removably clamped. A bushing 110 in the sliding sleeve 104 abuts against a flanged nut 112 which is threaded in the sleeve 104 and locked by a pin 114 entering a slot in the sleeve 74. Outside the sliding sleeve 104 is a removable ring 116 which serves as an extension of the frame and, threaded on the sleeve 104, is a stop nut 118 adapted to limit the inward movement of the sliding sleeve under the influence of the spring and the weight. The lower side of the sliding sleeve 104 carries a rack bar 120 actuated by a pinion 122 used only in the initial setup of the machine.' A guide shaft 124 is secured to the lower portion of the flange 108 and is guided in bearing bushings 126 of the frame.

The double row bearing 28 locates the abrading ring 12 and its spindle 24 in a definite location. When the nut 62, is screwed onto the rod 64, the rod is pulled to the left, lifting the weight 98 from the oor`and ultimately placing the scale beam above the horizontal. The reaction of the fulcrum pins 72 on the end of the sleeve 74 maintains a tension on the coil spring 102. As the grooved grinding members wear and as the balls are reduced in diameter, the weight will gradually sink and make the coil spring press the grinding member 10 against the balls at the uniform pressure predetermined by the position of the weight on the scale beam. The pressure exerted by the balls aganist the grinding members and tending to separate them is resisted or neutralized through the rod 64 and hence the grinding pressure does not tend to spread the supports of the grinding members. The spring pressure does not vary on account of any expansion of the spring because the weight makes the sleeve 74 and the washer 100 follow up the spring. In case any obstruction gets between the grinding members, the spring will give without having to suddeny overcome the inertia of the weight. The stop nut 118 is normally spaced from the ring 116 to allow the plate 10 and its sliding sleeve 104 to move towards the ring 12 during grinding. The ring 116 can be removed when the wheel 12 is Worn thin in'order to let the wheel 10 approach it.

Assuming that balls have been fed into the ball grooves by the feeding mechanism hereinafter described, they are carried around in the grooves for the greater part of a revolution by.

chute has an extension 134 provided with al series of tapped openings for a screw bolt 136 which passes through a slot in an angled bracket 138 clamped to the disc or flange 108. The screw bolt 136 provides for adjustment of the chute and stripper plate to take care of the wearing away of .the non-rotary abrading ring l0. The chute (Fig. 4) is also provided with a supporting lug 139 which res'ts on a screw 140 carried by a stud 141.

The feeding mechanism is carried above the machine by a standard 142 which is clamped to the bearing cap 106. The standard is provided with a horizontal rail 144 engaging in a channel 146 formed by lugs projecting from a hopper 148 which is conveniently made in two sections clamped together by screw bolts which engage a series of mating lugsl 150. The hopper is adjustable along the rail and clamped inadjusted yposition by bolts 152 passed through webs 154 on the hopper sections and entering selected openings 156 in the standard. Each hopper section has a sloping bottom wall 158 one of which is materially higher than the other. In a recess of the lower bottom plate is clamped a hardened plate 160 having a set of guide grooves 162 for the balls and the other bottom wall is provided with a flat guide plate 164, which is spaced from the grooved guide plate to form an outlet opening rfor the balls in the hopper. Each hopper section has a hollow enlargement 166 through which is passed a driving shaft 168 journaled in headed bearing bushings 170 in the ends of the enlargements. Each shaft 'carries a pulley 172 outside the vhopper and driven by a belt 174 which imparts to the shafts the same angular velocity in the same direction of rotation.

Inside the hopper, each shaft has keyed to it a hub 176. The hub in one hopper section has a series of spaced flanges 178 whose peripheries are undulating or scalloped as indicated at 180. On the other hub 176 is formed a similar series of spaced flanges `182 which are of larger external diameter than the other flanges but arranged in the same plane with them. The flanges are likewise in the same plane with the corresponding guide grooves 162 of vthe plate 160. The spaced flanges with their undulating peripheries form agitators and ball accelerators, the flanges 178 receiving the balls from the grooves 162 and tending to throw them downwardly out of the hopper. The ,other flanges 182 on the other hub move in the opposite direction at the hopper outlet and their function is to prevent the crowding of the balls into a feed passage and thereby guarding against the balls wedging or locking themselves in the passage. If desired, springs 1,921,886 .dulating flanges 178 and 182. The plates are concaved or cut away at 186 and 188 to clear the rotary hubs 176. The partition plates are rigidly spaced apart by a set of spacing plates `190 and a larger set of spacing plates 192 both sets being in the same plane and in the plane of the hub flanges. The partition plates and the spacing plates are assembled alternately and are rigidly secured togetherv by rivets or bolts 194. 'I'he adjacent edges 196 and 198 of the spacing plates form ball passages. The edges 196 are convexed or flared at their upper ends to form a blade edge 200 and the edges 198 are similarly rounded or convexed to form the blade edge 202. These blade edges are positioned close to the undulating flanges, portions of the spacing plates being concaved to clear such flanges. The crowned or flared surfaces guide the balls into the ball passages formed between the spacing plates. i

'I'he lower ends of the partition plates and the spacing plates are recessed at 204 to receive a rounded enlargement 206 on a chute plate 208 which is provided with U-shaped guide grooves 210. The grooves are closed for the greater part of their length by a cover plate 212 and at the top are closed by a top piece 214 (Figs. 3, 9and 10) whose upper end is also rounded to conform to the recess 204. The top piece has a pair of' apertured lugs 216 removably attached to apertured lugs 218 on the cover plate 212 by pins in the registering openings 220. The top piece 214 is also provided with end lugs 222 which have openings for bolts 224 entering tapped openings 225 in the chute plate 208. The upper ends of the guide grooves 210 flare outwardly as at` 226 and the top piece 214 has flaring grooves 227 so that the balls will be guided into them in different angular adjustments of the chute plate. This angular adjustment is called for by the desirability of moving the chute system to take care of the wearing away of the ring 10 and to provide for different ball sizes. The lower end of the cover plate 212 has at the front and rear a pair of slotted lugs 228 straddling thumb screws 230 which extend into tapped openings 231 at the front and rear of the chute plate 208.

The chute plate has a hollow enlargement 232 affording a chamber to which lubricating fluid, such as kerosene or soda water is admitted under pressure through apipe fitting 234, the other end of the chamber being closed by a plug 235. The chamber communicates with a set of ducts 236 which slant downwardly and communicate with the guide grooves 210. Fluid pressure jets passing through the ducts impart to the balls a velocity commensurate with the speed of the grinding wheel and since the speed of the grooves of different diameter is not the same, provision is made for varying'the speed of the jets to correspond. This is accomplished by coneended screws 238 clamped to the enlargement in adjusted position by nuts 240 and serving as throttle valves.

Another chute plate 242 having U-shaped guide grooves 244 has an enlargement at the upper end which is recessed or concaved at 246 to rockably engage the rounded lower end of the upper chute plate 208. Part of the socket is formed by a detachable bar 248 which is clamped to the chute plate by screw bolts 250 entering tapped holes 251 in the chute plate, the bar also having lugs 252 embracing the front and rear edges of the chute plate. 'Ihe guide grooves 244 are closed by a bent cover plate 254 having slots 256 at the upper end straddling thumb screws 258. The cover plate is further held by swinging bars 260 pivoted to the cover plate at 261 and having oppositely open slots 262 straddling headed screws 264 fastened to the chute plate. The chute plate hastwo pairs of apertured lugs 266, each pair being pivoted to a bent supporting arm 1268 detachably resting against a slanting lug 270 carried by a supporting plate 272. The arms 268 are connected for simultaneous operation by a rod 273. The chute plate 242 has at its lower end a pair of apertured lugs 274 each pivoted between a pair of lugs 276 of the supporting plate 272. 'Ihe` lower end of. the chute plate has a square cornered recess 278 to detachably receive a hardened plate 280 having grooves 282 to form continuations of the guide grooves 244.

The grooves 282 deliver the balls substantially tangentially into the grinding grooves at the point where the labrading ring 10 is interrupted at the front of the machine and each ball goes into its grinding groove on the wheel 12 at a speed substantially. equal to half the speed of the grinding groove. This enables a much greater number of balls to be ground than could be obtained by a mere gravity feed of the balls unless that gravity feed were extended to an unreasonable height. The guide grooves 244 not only have a lateral curvature by reason of the bent chute plate 242 but the grooves themselves curve laterally of the chute plate soy that when the balls meet the revolving wheel they are being impelled substantially in the same direction. The passage of the balls and the liquid through the grooves is comparable to the flow of liquid in a pipe and so there is little diminution in velocity around any gradual bend.

The supporting plate 272 rests on a ledge 284 where the flange 108 is interrupted and is adjustably secured by a T-headed bolt 286'to a slotted extension 288 on an angled bracket 290 fastened to the ilange 108 and also resting on an adjusting screw 292 carried by a stud 294 The T-headed bolt and slot afford a horizontal adjustment of the lower chute plate to take care of' the proper guiding of the balls when the ring 10 has become thinner during grinding. 'Ihis adjustment does not change the relative positions of the chute plates in any material degree because the rounded socket at the joints allows the chute plates to adjust themselves to one another without impairing the substantial alignment of the ball guides. 'Ihe chute sections readily come apart inasmuch as the lifting of the bent supporting arm 268 over the lug 270 will then allow the lower chute section to be swung down around the pivot pin at its lower end and the upper section dropping out of the recess 204.

The balls at the hopper outlet obtain an initial velocity due to vthe accelerating eiect of the wheel 178 and gravity continually adds to the velocity. As the balls pass the throttle valves 238, the jets of liquid impart a still greater velocity to the balls, each jet being regulated to impart to the passing balls a velocity which will carry them to the grinding wheel at half the speed of the respective groove in which the balls are to be ground. Thus each groove will operate on a plurality of balls at each revolution whereas, in prior machines, the balls have been inserted so slowly that there is an average of less than one -ball to a groove. f

In Figs. 18 and 19 there is indicated a modification wherein the balls are given progressively varying initial velocities by a cone feed wheel 300 having flanges 302 provided with undulations on the periphery. The diameters of the anges 302 ,are proportioned to the diameters of the grind-- ing grooves to give high initial velocities corresponding to half the speed of the grinding grooves but somewhat slower and to feed varying numbers of balls proportioned to the varying diameters of the grinding grooves.

I claim:

1. In a ball grinding machine, a rotary grinding wheel having ball grooves, an opposed grinding member movable with respect to the grinding wheel, ball guides communicating with the grooves, means for feeding balls into the guides, means for adjusting the ball guides with respect to the movable grinding member, a support for the ball feeding means, and the ball guides having self-adjusting connections with the ball feeding means; substantially as described.

2. In a ball grinding machine, a rotary grinding wheel having ball grooves, an opposed grinding member movable with respect to the grinding wheel, ball guides communicating with the grooves, means for feeding balls into the guides, means for adjusting the ball guides with respect to the mdvable grinding member, a support for the ball feeding means, the vball guides having self-adjusting connections with the ball-feeding means, and means for adjustably securing the feeding means on the support; substantially as described.

3. In a ball grinding machine, a rotary grinding wheel having ball grooves, an opposed grinding member, ball guides communicating with the grooves and comprising a plurality of sections, one of said sections being tiltably supported and having a seat for supporting the other section; substantially as described.

4. In a ball grindingmachine, opposed grinding members, means for rotating one of said members, a spring for pressing one of said members towards the other to produce grinding pressure, a shaft, a sleeve slidable on the shaft to back up the spring, a lever pivoted to the shaft, and a weight holding the lever pressed against the sleeve; substantially as described.

.5. In a ball grinding. machine, opposed grinding members, means for rotating one of said members, a spring for pressing one of said members towards the other to produce grinding pressure, a shaft, a sleeve slidable on the shaft to Y back up the spring, a lever pivoted to the shaft, a weight holding the levei` pressed against the sleeve, and means for effecting longitudinal movement of the shaft to apply leverage to the sleeve; substantially as described.

6. In a ball grinding machine, opposed grinding members, means for rotating one of said members, a spring for pressing one of said members towards the other to produce grinding pressure, a shaft, a sleeve slidable on the shaft to back up the spring, a lever\pivoted to the shaft,

a weight holding the lever pressed against the,

sleeve, means for effecting longitudinal movement of the shaft to apply leverage to the sleeve, and an abutment for taking spring pressure from the sliding sleeve when the leverage is removed; substantially as described.

7. In a ball grinding machine, opposed grinding members, means for rotating one of said members, a spring for pressing one of said members towards the other to produce grinding pressurefa shaft, a sleeve slidable on the shaft to follow up the spring, a lever pivoted to the shaft and resting against the sleeve, a weight tending to swing the lever in one direction, and a nut threaded on the shaft and resisting longitudinal movement thereof; substantially as described.

8. In a ball grinding machine, opposed grind- 'ing members, means for rotating one of said members, a slidable carrier for the other of said members, a guide for the slidable carrier, a shaft, a spring engaging the slidable carrier, a lever pivoted to the shaft, and means for causing the lever to apply a predetermined pressure to the spring to produce uniform grinding pressure; substantially as described.

9. In a ball grinding machine, opposed grinding members, means for rotating one of said members, a slidable carrier for the other of said members, a guide for the slidable carrier, a shaft, a spring engaging the slidable carrier, a lever pivoted to the shaft, a weight for causing the lever to apply a predetermined pressure to the spring to produce uniform grinding pressure, and means for sliding said shaft to control the action of vsaid lever and weight; substantially as described.

10. In a ba". grinding machine, a rotary grinding wheel having ball grooves, ball guides communicating with the grooves, a hopper having partitions forming individual ball passages leading to the guides, and a feed wheel having fanges operating between the partitions; substantially as described. v

1l. In apparatus of the character described, ball guides, a hopper, la feed wheel having undulating flanges for propelling balls from the hopper to the guides, .and means for agitating the balls to prevent them from jamming together; substantially as described.

. GEORGE F. MA'ITESON. 

